1. Field of the Invention
The present invention relates to an electronic camera having a continuous shooting function. More specifically, the present invention relates to an electronic camera capable of achieving higher speed in continuous shooting.
2. Description of the Related Art
The technologies for achieving a higher speed in continuous shooting in electronic cameras in the known art include the following. Japanese Laid-Open Patent Publication No. H6-54252 discloses a technology whereby the continuous shooting speed is increased by simultaneously performing exposure of the subsequent frame on the image capturing element side while compressing the image in the preceding frame.
Japanese Laid-Open Patent Publication No. H5-191700 discloses a technology whereby the length of the image read time is reduced by reading out an image signal every few lines from the image capturing element to achieve higher speed in continuous shooting. Japanese Laid-Open Patent Publication No. H7-135589 discloses a technology whereby the length of the image recording time is reduced by dividing the data of an image that has been captured to be recorded onto a plurality of recording media to achieve a higher speed in continuous shooting.
The following problems arise with the prior art technologies described above.
In regard to the technology disclosed in Japanese Laid-Open Patent Publication No. H6-54252, if the exposure time is longer than the length of time required for compression processing, the exposure operation and the compression processing operation are executed continuously with a high degree of efficiency. As a result, the full advantage can be achieved. However, if the exposure time is shorter than the compression processing time, the image capturing element side must remain in a standby state for the read of the image in the succeeding frame until the compression processing of the preceding frame is completed. Thus, the continuous shooting speed is reduced by the length of time corresponding to the wait time.
The technology disclosed in Japanese Laid-Open Patent Publication No. H5-191700 requires the use of a special image capturing element that is capable of reading out the horizontal lines by specifying individual lines and thus presents a problem in that a general-purpose image capturing element cannot be utilized.
The technology disclosed in Japanese Laid-Open Patent Publication No. H7-135589, which requires a mechanism for mounting a plurality of recording media and recording circuits, makes it difficult to achieve miniaturization of the electronic camera and a reduction in the cost.